Bending machine



Sept. 4, 1962 Filed July 14, 1959 E. STEG MAN N BENDING MACHINE 2 Sheets-Sheet 2 Fig.3

IN VEN TOR.

In: err-pens) hired rates Pater 3,ll52,277 Patented Sept. 4, 1962 3,052,277 EENDTNG MACHINE Ernst Stegmann, Viilnachern, Switzerland, assignor to Firma Arno H. Wirth, Wurttemberg, Germany Filed July 14, 1959, Ser. No. 827,422 Claims priority, application Germany .luly 17, 1958 8 Claims. (Cl. 153*15) The present invention relates to improvements in a bending machine for round and flat stock of the known type of construction in which a plurality of slide-carriage units are mounted on the work table around a central die which is disposed in a recess in the work table, and in which the tool carriers which are slidahle within the slide beds are adapted to reciprocate relative to the con tral die. The elongated Wire or strip material which is supplied by a special feeding device is then bent between the die and the tools and around the die.

In the bending machine of this type known prior to this invention, the slide units have carriages which are guided in a direction extending radially to the central axis of the die, and the slide units themselves are rigidly mounted on the work table which, in turn, is rigid with the machine frame.

In order to convey the workpieces, which are produced in a continuous work cycle by bending the wire or strip material, in a simple manner away from the place of work, the work tables are strongly inclined relative to the horizontal plane thereof so that the finished workpieces can slide by their own gravity out of the area where the work is carried out. For setting up the tools, it is, however, very undesirable to have a work table which does not lie horizontally.

It is an object of the present invention to eliminate this disadvantage by mounting the work table together with the die and slide units as well as the driving means therefor so as to be pivotable on the machine frame about a horizontal axis.

A bending machine of such a design may then be set up while the work table extends within a horizontal plane, while during the operation of the machine the work table may be moved to any desired inclination in accordance with the particular workpiece concerned and the operation to be carried out thereon, and it may even be moved to an inclination exceeding 90 relative to the horizontal plane.

In many operations carried out on such a machine, especially when working on a spring-tempered material, it is necessary to bend such a material beyond the angle required in the final condition. With the known bending machines this can be done only to a limited extent by making the die of a suitable shape.

In order to increase the versatility of the machine in this respect considerably, the present invention further provides that the slide units are mounted on the Work table so as to be adjustable and locked in a fixed position, and so that the bearing neck of the pinion, which is provided for driving the tool carrier and meshes with a central driving gear, will rest on the inner edge of a recess in the work table which extends coaxially to the driving gear. Such a manner of supporting the slide unit has the advantage that, regardless of the position in which the slide unit is clamped upon the work table, the proper axial distance between the axis of the pinion and the axis of the driving gear will always be maintained so that the slide pinion will always be properly meshing with the central driving gear. The direction of operation of the tools guided in the slide is thus no longer limited to a radial direction extending through the central axis of the machine and die, but it may also extend laterally past this central axis at any desired angle, thereby permitting 2 the workpiece to be bent beyond the angle required in the final product.

In the known bending machines of this kind, the feeding device for the material is mounted rigidly on the work table in such a manner that the rectilinear feeding direction of the material will extend at a sufficient distance from the central axis of the machine in order to prevent the material while being fed from colliding with the thickest possible die. However, after a piece of wire has been fed and cut cit by the first tool and is then to be bent to form the desired workpiece, the same has to be placed in engagement with the lateral surface of the die, which requires a special device on this tool for gripping, holding and feeding the workpiece to the die. These operations have to be carried out very accurately which is very difiicult to attain.

These disadvantages and difiiculties occurring in the prior bending machines may be eliminated. according to the invention by providing a bending machine with a feeding mechanism which has a rectilinear direction of feed of the material toward the die and which is adapted to be adjusted and locked on the work table in such a manner that the adjustment can be carried out at least in a direction parallel to the plane of the work table. The feeding mechanism may then be designed and directed so that the wire will be in a lateral engagement with any die regardless of the shape thereof, even while it is being fed and without any special auxiliary means of the first tool.

Aside from an adjustability of the feeding mechanism parallel to the plane of the work table, it is also advisable to provide for an adiustability of this mechanism in a direction at right angles to such a plane particularly if the machine is to be used for bending sheet and strip material.

In order to increase the versatility of a bending machine of the mentioned kind, the present invention further provides that the bearing neck is mounted underneath the actual slide bed on a slide base in which not only the shaft of the mentioned pinion but also a gearing as well as a shaft are mounted which carries the cam plate and is driven by the gearing. The bearing neck is then laterally offset in the axial direction of the slide relative to the mentioned shaft. With a slide unit of such a construction it is possible to place the point of securement of the bearing neck on the slide bed much more closely to the actual point of working engagement of the tool since the cam shaft which is offset toward the rear is still disposed at a sutficient distance from this point of working engagement which is determined by the length of the slide and the slide stroke and by the diameter of the cam plate.

Particularly with such a separate camshaft, but also with a shaft which carries the pinion as well as the cam plate, it is also possible to increase the clamping possibilities to a further extent by utilizing the cam shaft carrying a pair of cam plates and by providing the slide on suitable arms thereof with two stop members which are diametrically opposed to each other and one of which cooperates with one cam plate and the other with the other cam plate. in such a case, the return stroke is not dependent upon the force of a spring which is not capable of overcoming certain obstructions, but it will be positively actuated.

The application of a pair of cam plates permits the further modification of providing exchangeable intermediate elements on the cam shaft for securing the cam plates thereon. By such exchangeable elements it is possible to vary the vertical position of the cam plates in such a manner that the paths of travel of this pair of cam plates can intersect with the paths of travel of the pair of cam plates of a closely adjacent slide unit.

These and other objects, features, and advantages of the present invention will become further apparent from the following detailed description thereof, particularly when read with reference to the accompanying drawings, in which FIGURE 1 shows a diagrammatic longitudinal section of the machine according to the invention;

FIGURE 2 shows a top plan view thereof;

FIGURE 3 shows a longitudinal section of a modification of the slide unit on a larger scale; while FIGURE 4 shows a longitudinal section similar to that of FIGURE 3 and of the same slide unit, but illustrating a different manner of securing the pair of cam plates.

Referring to the drawings, and first particularly to FIG- URES l and 2, the machine frame I supports a work table 4 of a hollow construction which is rotatably mounted on two trunnions 3 and 5 so as to permit it to be pivoted within an angle of 360. This pivoting movement may be effected either by a hand crank or, as indicated in FIGURE 1, by a worm gearing, depending upon the size of the machine. In the position of the machine as illustrated in FIGURE 1, the actual Working surface of the work table faces upwardly. This upper work surface has a circular aperture 4a therein extending coaxially to the central work axis of the machine and containing a circular mounting plate 11 which is rigidly secured to the work table 4 by means of a central hollow shaft It), which is adapted to receive and support the die a, and by transverse ribs 4!). Mounting plate 11 has a circular T-shaped clamping groove 11a extending coaxially to the central work axis of the machine. By means of clamping bolts, not shown, and by means of clamping claws or the like, also not shown, which are mounted on or engage with the slide bed 12 of each slide unit, the latter may be clamped in any fixed position of adjustment with respect to the mounting plate so that the downward portion or projecting bearing neck 12a of slide bed 12 extends through the gap defined by the work table and the mounting plate and engages with the wall of the abovementioned circular aperture 4a. This is of importance to insure the proper engagement of the gears of the operating or drive mechanisms of the tool carriers 15, 15" which are adapted to reciprocate within the respective slide beds 12, as subsequently described.

This drive mechanism consists of a motor 18 within the machine frame l which, through a V-belt and through a pulley 17, drives a shaft 6 which is mounted within the one trunnion 5 and carries a bevel gear 7 which drives another bevel gear 8. This bevel gear 8 is integrally secured to a spur gear 9 and rotatably mounted with the latter on the hollow shaft Itl. Spur gear 9 forms the central driving gear or operating means for all pinions 14 of the various slide units. A proper meshing engagement between each pinion M and gear 9 will be insured by the engagement of the respective bearing neck lie with the Wall of the circular aperture in in work table 4, regardless of the manner in which the slide units are clamped upon the mounting plate .lll. The same shaft on which the motion transmitting pinion 14 is mounted also carries a motion transmitting cam plate 13 "which is adapted to effect the reciprocating movement of the slide or tool carrier (l5, I5, 15'') of each slide unit which is guided within the slide bed 12.

As shown in FIGURE 2, a wire feeding mechanism 16 which includes wire straightening and feeding rollers is secured to work table 4. The direction of feed intersects with the central work axis of the machine, as i11- dicated in dot-and-dash lines in FIGURE 2. By mounting the feeding mechanism so as to be adjustable, it is possible to adjust this rectilinear direction of feed in the vertical direction, that is, in a direction parallel to the plane of the work table if the latter stands vertically, and also in a direction at right angles thereto, that is, in the direction of the width of a strip material and vertically i to the plane of the work table if it stands in the vertical position.

In the embodiment of the invention as above described, the work table therefore takes up all the stationary and movable parts in such a manner that it will be capable of pivoting to any angle while the machine is running. If the bending machine is one of a larger size, the driving motor may also be mounted within the hollow work table and be coupled directly to the drive shaft 6. The tool carriers 15 are urged into engagement with the re spective cams 33 by springs 21 each of which has one of its ends connected to the respective carrier and another end connected to the work table 4.

The machine of FIGS. 1 and 2 operates as follows:

The die Ida carries a vertically reciprocable mandrel lltlc whose outlines correspond to the configuration of the product which is to be shaped in the bending machine. When it projects upwardly and beyond the die Me, the mandrel lhc is adjacent to the path of the wire 16]) shown in heavy phantom lines) which extends forwardly and beyond a feeding member forming part of the mechanism 16. When a bending operation is completed, the feeding member 16a advances a predetermined length of wire 16b to a position in which the wire may be engaged by the tips of the tools on the tool carriers 15, f5, 15".

In the next step, the tool carrier 15 is operated to move its bending tool 15a toward the mandrel file so that the tip 15c of the tool 15a deforms the wire 16b by bending it about the adjacent portion 10d of the mandrel. In a subsequent step, the tool carrier 15 is advanced toward the mandrel so that the tip of its tool 15b bends the wire ll6b about the adjacent portion of the mandrel Mic. The front portion of the wire 16b has now assumed the general shape of the ultimate product and is thereupon severed by the cutting tool 15e of the tool carrier 15'', this cutting tool cooperating with the lefthand end face of the feeding member 16a when the carrier 15 is moved toward the die 10a. The cutting tool 15c simultaneously deforms the rear portion of the ultimate product by bending it about the mandrel 100.

The mandrel is then withdrawn into the die 10a and the tool carriers 15, I5, 15 are moved away from the die so that the ultimate product descends by gravity into a suitable receptacle placed next to the frame 1. The table 4 may remain in inclined position during a full series of bending operations since the inclination of the table in no way affects the operation of the tool carriers.

According to the modification of the invention as illustrated in FIGURES 3 and 4, the bearing neck 12a is provided on a special bottom plate 20 to the upper side of which the actual slide bed 12 is secured by bolts, not shown. This slide bed 12 is provided along two-thirds of its length, as shown at the right side of FIGURES 3 and 4, with a dovetail guide 21a for the slide or tool carrier 15, while the other third of slide bed 12, as shown at the left, has the full thickness.

Bearing neck 12a supports a shaft 23 which is rotatable therein by means of ball bearings and carries on one end thereof the pinion 14- which has already been described in connection with FIGURE 1. The other end of shaft 23 carries a gear 2'4 within a recess in the bottom plate 2t This gear 24* meshes with a further gear 25 which, in turn, engages with a gear 26 which is keyed to the actual cam shaft 2'7. The upper end of shaft 23 is mounted in a corresponding aperture in slide bed 12. The ends of the shaft carrying gear 25 are mounted at one side in an aperture in bottom plate 20 and at the other side in an aperture in slide bed 12. The recessed end of cam shaft 27 is supported in a suitable bearing in bottom plate 20, while the thicker part of the cam shaft is mounted in a strong ball bearing 28 in the thicker part of slide bed 12. In the form of the adjustment of the ma chine according to FIGURE 3, cam shaft 27 further carrics above ball bearing 28 a spacing ring 29, an intermediate annular member 30 and further intermediate annular members 31 and 32. All of these members 29 to 32 are clamped by a cap 33 and a screw 34 to shaft 27 and against ball bearing 28.

The intermediate member 3% which is for this purpose provided with a collar carries the two cam plates 35 and 37 which are secured to the opposite sides thereof by screws 36 and 38, respectively, and are therefore in a fixed relative position to each other. The cam surface of cam plate 35 is in engagement with a roller follower 39 which is mounted in the crosshead of a bolt 40 which extends eccentrically to such end portion and is provided with screw threads for screwing bolt 4%) into a tapped bore 22b in the tool carrier 15 and for locking it in a fixed position by nuts 41. Cam plate 35 thus effects the work feed of slide or tool carrier 15 to which the tool is to be clamped at A in any suitable manner not shown. The upper side of the tool carrier 15 carries an arm or bracket 43 which is secured thereto by screws 42 and sup ports on its free end the bearing shaft 44 of a further roller follower 45', the cam surface of which engages with the second cam plate 37. In this embodiment, cam plate 37 effects the return stroke of the tool carrier 15.

In the form of adjustment of the machine according to FIGURE 4, the spacing ring 29 is omitted and the annular member 30 is instead clamped directly against the bearing 28. Cam plate 35 is in this case clamped upon the upper side of member 3%) by means of screws 46 which are also used for securing a second annular member 47 to the upper side of cam plate 35'. The upper side of this annular member 47 which is likewise provided with a collar calries the upper cam plate 37 which is secured thereto by screws 38. Then again follows the intermediate annular member 31. The last annular member 32 as shown in FIGURE 3 is omitted in the embodiment according to FIGURE 4, and cap 33 is clamped by screw 34 directly against the annular member 31. In accordance with the different vertical position of cam plates 35 and 37 caused by the different arrangement of the spacing rings, roller 39 which engages with the cam surface of cam plate 35 is placed in FIGURE 4 at a higher level than in FIG- URE 3. This is attained by the provision of adjusting means in the form of a bolt 4-0 and by a turning of this bolt about its axis through an angle of 180. The difference in level of the staggered cam plate 37 is compensated for by a spacing member 48 and by the use of longer screws 49.

By thus raising the position of cam plates 35 and 37, the lower cam plate 35 will be staggered with respect to the cam plates 35 and 37 in FIGURE 3, while cam plate 37 is also staggered with respect to its former position. In this manner it is possible to mount two adjacent slide units so closely adjacent to each other on the work table that the paths or" travel of the respective pairs of cam plates will overlap each other. This is of importance particularly because many workpieces require two pairs of slides to be moved as closely as possible toward each other which in the prior bending machines of this type was rendered impossible since the path of travel of each set of cam plates determined the closest possible distance between two adjacent slide units. Consequently, the different possibilities of mounting the cam plates according to the invention also considerably increase the number of possibilities of mounting the slide units.

Although my invention has been illustrated and described with reference to the preferred embodiments thereof, 1 wish to have it understood that it is in no way limited to the details of such embodiments, but is capable of numerous modifications within the scope of the appended claims.

Having thus fully disclosed my invention, What I claim is:

1. In a bending machine for elongated round and flat stock, in combination, supporting frame means; hollow work table means mounted in said frame means for rotation about a substantially horizontal axis, said work table means formed with aperture means; mounting means received in said aperture means and fixed to said work table means; a plurality of slide units adjustably connected with said mounting means and movable with respect thereto about an axis substantially perpendicular to said first mentioned axis, each of said slide units comprising a portion extending into said work table means; a tool carrier mounted on each of said slide units; means at least partially received in said work table means and operatively connected with said portions for operating said tool carriers; and means for rotating said work table means with respect to said frame means.

2. The combination as set forth in claim 1, wherein said work table means is rotatable through 360 degrees.

3. In a bending machine for elongated round and flat stock, in combination, supporting frame means; hollow work table means mounted in said frame means for rotation about a substantially horizontal axis, said work table means having a work surface formed with aperture means; mounting plate means received in said aperture means, said mounting plate means defining an annular gap with said work surface and comprising coaxial die supporting means fixed to said work table means; a plurality of tool carriers disposed about said die supporting means; a slide unit for each of said tool carriers, said slide units adjustably connected with said mounting plate means and movable with respect thereto in a circle about the axis of said die supporting means and each thereof comprising motion transmitting means for reciprocating the respective tool carrier with respect to said die supporting means, said motion transmitting means comprising a portion extending through said gap and into said work table means and a pinion mounted in said portion and located in said work table means; means for operating said motion transmitting means comprising a gear provided in said work table means, coaxially surrounding said die supporting means and meshing with said pinions, and means for rotating said gear; and means for rotating said work table means with respect to said frame means.

4. In a bending machine for elongated round and flat stock, in combination, supporting frame means; hollow Work table means mounted in said frame means for rotation about a substantially horizontal axis, said Work table means having a work surface formed with aperture means bounded by a circular wall; mounting plate means received in said aperture means and defining an annular gap with said circular wall, said mounting plate means comprising coaxial die supporting means fixed to said Work table means; a plurality of tool carriers disposed about said die supporting means; a slide unit for each of said tool carriers, said slide units adjustably connected with said mounting plate means and movable with respect thereto in a circle about the axis of said die supporting means and each thereof comprising motion transmitting means for reciprocating the respective tool carrier with respect to said die supporting means, each of said motion transmitting means comprising cam means engaging with the respective tool carrier, a bearing neck rigid with the respective slide unit, said neck extending through said gap and abutting against said circular wall, a shaft rotatably received in said neck and operatively connected with the respective cam means, and a pinion located in said work table means and secured to the respective shaft; means received in said work table means for operating said motion transmitting means, said operating means comprising a central driving gear coaxially surrounding said die supporting means and meshing with said pinions; means at least partially received in said work table means for rotating said central supporting gear with respect to said work table means and for thereby reciprocating said tool carriers with respect to said die supporting means; and means for rotating said work table means with respect to said frame means.

5. The combination as set forth in claim 4, wherein each of said slide units comprises a slide bed rigid with the respective bearing neck, a cam shaft mounted in said slide bed and connected with the respective cam means, and means for drivingly connecting said first mentioned shaft with said cam shaft.

6. The combination as set forth in claim 4, wherein each of said cam means comprises two spaced cam plates and each of said motion transmitting means comprises two followers each connected with the respective tool carrier and each engaging with one of said cam plates for respectively moving the tool carrier in two opposite directions when the respective pinion is driven by said central gear.

7. The combination as set forth in claim 6, further comprising spacing means for staggering the cam plates of at least one of said motion transmitting means with respect to the cam plates of the other motion transmitting References Qited in the file of this patent UNITED STATES PATENTS 1,377,150 Hagstrom May 3, 1921 2,614,605 Senna Oct. 11, 1952 2,820,505 Franks et al. Jan. 21, 1958 2,871,909 Bower Feb. 3, 1959 2,920,676 Tnrnblade Ian. 12, 1960 i l l 

